Analysis Toolpak-Confidence Level and data analysis questions
 

Hi,

I used the Analysis Toolpak-Regression Analysis with the box for Confidence
Level checked and a value entered. I did this for 6 different sample sets,
condition a and condition b, each for 2 different lots of the same sample
type and for all the data within each condition. I got back 6 tables with
various data, including a single value for both the upper and lower
confidence for each. What I need to do now is the following:

1. Display a regression line for the data both graphically and numerically.
I did this
by adding a trend line with equation and r shown, to the data of interest
and selecting the regression/power that resulted in an equation with values
closest to that obtained by the analysis toolpak regression data described
above. Is this the correct way to do this? Is there a better way?

2. predict an endpoint for the overall condition and for each lot/condition
by using the confidence line. I need to display a confidence line for the
upper and/or lower confidence level both graphically and numerically to show
the point at which the confidence line intersects the x axis at a specific y
value. I'm not sure how to do this. The Help features were not useful
either.

3. determine if there is a significant difference between the data sets
analyzed both between lots and between conditions as well as overall for all
lots combined between conditions. I'm not sure how to do this. The Help
features were not useful either.

I appreciate any help you can provide in this matter.

Sincerely,
MH